step 1 : replace $A\implies B$ by $\lnot A \lor B$
step 2 : replace $\lnot(A\lor B)$ by $\lnot A\land\lnot B$ and $\lnot(A\land B)$ by $\lnot A\lor\lnot B$
step 3 : use distributivity of $\land$ relatively to $\lor$, that is $(A\land B)\lor C=(A\lor C)\land(B\lor C)$
step 4 : use associativity of $\land$ to remove some superfluous parenthesis
Normally you should get this 3 km long formula...
$(\lnot P\lor R)\land(\lnot Q\lor R)\land (\lnot P\lor S)\land(\lnot Q\lor S)\land (\lnot P\lor T)\land(\lnot Q\lor T)$